The first was found above the entrance to Potomac High, and school officials immediately removed it. Six more followed, placed on exit signs, lockers and a police vehicle belonging to the school's resource officer, before police were able to make an arrest, said Ken Blackstone, a school system spokesman.

Joseph W. Barnes, 18, was arrested Tuesday and charged with five counts of destruction and defacing property. Blackstone said the Potomac High student, who is due in court June 24, is not in school and that the case is being handled according to the school system's code of behavior. Blackstone said he could not comment further on individual disciplinary actions.